On my 1991 S10 Blazer 4x4 SUV the front wheel drive transfer case is directly under the driver's feet. I never use the 4x4 but I sometimes hear a noise coming from that area. When yoiu change your oil, it may be wise to at least inspect the fluid level or completely change the transmission fluid (Dextron III) in the 4x4 transfer case. That is a simple job. The fill and drain plug are large (over 1 inch) metric plugs. The largest expense is purchasing a metric socket that size or maybe I can borrow one. The 4x4 transfer case is chain driven and chains become noisy without adequate lube. However, I don't think the chain is moving if the 4x4 is not engaged but I don't know for sure.

The fluid in the 4x4 transfer case on my 1991 S10 Blazer has never been changed and I see no sign of any leaks so I suppose the transmission fluid in the transfer case is probably just worn out. I changed the filter and fluid in my transmission recently and it was still bright red, meaning, it was good. I think the previous owner (my daughter) had the transmission fluid changed sometime since she bought the car in 1991. My 1991 S10 Blazer is in amazingly mint condition for a 18 yerar old car and even has the original spare and tire cover hanging on the tail gate.

Well, I took my car to the mechanic yesterday. He told me my differential was going out.....$1,500! I just put $900 in it for a new fuel pump. I told him I would give him $5.00 to drive it off a cliff. I also asked if he thought someone would steal it if I left the keys in it! No takers. A thief doesn't even want it. He told me it would either go out and coast to the side of the road or could possibly lock up the rear wheels and put me into a skid. Oh, goodie! He also told me I need new tires. So, I am not very happy!

I have a 1996 chevy blazer and my lights keeps going off intermittently. During that time I can hear noise coming from my glove box. I changed all 3 relay switches in the glove box and to no avail, my lights still keep going off. I spoke with several people who told me it could possible be my turn signal arm or a poor connection. Need some assistance.

The Gov-Loc rear differentials used in the S10 Blazers and other GM intermediates are good units if they are not abused. They are a unique locking - unlocking type differential and they work well for their intended use. The Gov-loc differential will sense relative wheel speed and when one rear wheel is spinning 100 RPM faster that the other, the Gov-Loc will lock up and engage both axles. The when the vehicle reaches 20 MPH, the Gov-loc will disengage the axles and function as a conventional differential. Spinning one rear wheel in gravel or mud and if the other wheel hits solid pavement the subsequent impact shock to the differential when it locks the axles will instantly destroy a Gov-Loc. .Richmond makes a No-Slip differential that costs $400 and is a direct replacment for the Eaton Gov-Loc differential used in GM intermediates. Te Richmond No-Slip differential will stand mose any kind of abuse with an engine with up to 275 to 300 HP. The Richmond No-Slip differential is a locking type differential that may be troublesome for some people to drive on the street but it is far more durable than a Gov-Loc. The Eaton Gov-Loc replaced the clutch type limited slip differentials that GM first introduced in 1957.. The old clutch type limited-slip differentials required whale oil as a friction modifier additive. Whale oil is not available anymore to use as a friction modifier because of the international restrictions against harvesting whales for their oil.

Look on your glove compartment door for RPO code G80. If that code is on the RPO decal on the glove compartment door, you have the troublesome Gov-Loc differential.

Get a second opinion. While it is possible for a high mileage, or heavy towing, to kill the bearings in the diff, that $1500 estimate is high. A complete rebuilt or used unit is what he is quoting, and if you can find a good drivetrain shop they should be able to re-use something out of the original. The typical failure I have seen is the pinion gear bearing, and many times that is caused by having the pinion shaft seal replaced and the bearing being over torqued on reassembly. Very, VERY common on Chevy differentials. You really need to make sure you are dealing with someone who understands that the Chevy has very specific torque specs, and to exceed them will kill the differential.

Well, well, well, Ladies and Gentlemen....the mystery is solved. My problem was a wheel bearing. The first mechanic (?) said my differential was going out and that it would cost $1500. The second mechanic wanted $50 to diagnose my problem but that I had a wheel bearing going out. I finally found a FABULOUS mechanic on Angie's List. He diagnosed the noise as a wheel bearing immediately. He fixed it that afternoon for less than $450. I would have been SICK to have spent $1500 on a rear differential and then found out it was a wheel bearing later. So, I am back on the road! Kat

I keep telling everyone that I am trying to build a new car a piece at a time. So many things have gone wrong in a year-and-a-half. I'm afraid of what is next. I have replaced the brakes twice, alternator, serpentine belt, fuel pump, wheel bearing, and ball joints; and my water pump has supposedly been going out for a year. I have lived in my current apartment for one year and have had my car broken in to three times (the last time breaking out the window). So, I am pretty exhausted at this point.

A year ago, a mechanic gave me a price of $250. The most recent estimate was approximatley $450. I am a single woman, so I can't do it myself (not that a woman is not perfectly capable. It's just that "I" am not). Maybe when my boyfriend comes home I can have him fix it.

While driving fast but more noticable when slow, going straight with AC on or off and in 2 or 4 wheel drive there is a knocking that I can feel on my left foot. It becomes more distinct the longer I've been driving. Any ideas? I just had new tires put on as well as a new oxygen sensor but I think I remember it before I had those repairs made. I crawled underneath and looked around but don't see anything obvious or even many functioning parts around the suspect area. Any suggestions would be great. Thanks.

Own a 2000 chevy blazer. Makes a loud almost revving noise when its cold. noise will stop when you come to a stop and does not come back until the car is shut off. also when you stop it makes a clunking noise. any ideas. very similar to #107. almost the exact same thing. please help.

Very common for the fan clutch on a 4.3L to be very loud when first started and for the first few minutes. Not a concern unless the noise continues, indicating the fan clutch has locked up. This will kill your gas mileage, and also cause the engine to run cool.

No not like a fan clutch noise. Best way to describe is like the card in the bike tire. Only happens when the engine is cold. not even cool. I let the car sit for 3 hours and tried to make it happen and it wouldnt because it was still warm. Sounds like it is in the passenger side of the blazer. And the noise stops if you come to a stop sign and does not come back until next day or hours later. Im stumpped.

Ok i was reading your earlier posts and read something about a throttle cable. I noticed that my outer cable keeps popping off. This is my grandmothers car. When i say outer cable i mean one on passenger side of throttle control. i put it back on and pushed the clip in and it does not fall off anymore. I did this last night and she told me that when she started the car to go to work today it did not make the noise. i do not see how that clip not being on the cable could affect anything. This noise is pretty loud. sounds like an airplane propeller under the hood. i am going to rule out the blower as it does it whether the blower is on or off. I also realized that when i said it sounds like it is coming from passenger side i was sitting in the drivers seat so it could be middle of engine over. I am pretty handy with cars and have heard all kinds of noises but this one has me. car does not seem to run diffrently. but i want to fix it before it gets worse.

And now for another problem.Grandfather has a 94 GMC Sonoma. 4.3L vortec. We rebuilt the motor about a year and a half ago. it had spun a bearing and we bought it that way. Replaced the crank and had rods cut and new bearings all around. New knock sensor. Lately he noticed that at low RPM's the motor shakes pretty rough. plug on knock sensor was broke so i replaced it. same problem. this motor has a balance shaft in it and i fear it is something to do with that. any ideas are greatly appreciated. if more info is needed please let me know. once highway speed is reached shake goes away as long as you are on throttle. if pedal is in only a little shake is at its worst. i believe timing is good. 12 degrees one way or the other i dont remember. will check it again tomorrow. is my timing off? what should it be? truck still has plenty of power. blows smoke and smells real rich. please help.

I hear what sounds like a metallic rattling that seems to be coming from under the driver's side of my 2000 blazer. While on ramps I've shaken every possible thing I can find to grab hold of and can't find anything loose. A muffler shop told me that the inside of the catalytic converter is probably worn out and causing the noise. Could this be so and can it just be cut out or would running without the catalytic converter cause the engine to not run correctly.

Running without the converter could cause issues as this vehicle has a "closed loop" system for controlling the fuel injection. If the converter has come apart inside, it will sound something like marbles inside a coffee can.

A good source for used parts, converters included, is an eBay store named "s10warehouse".

I am in no way affiliated with these guys, other than having bought a LOT of used parts from them with very, very good service.

just bought a new blazer and about 2 weeks ago it started squeaking sounded like the belt was loose so i replaced the tension pulley and the idler pulley started it up and no sound 1 day later the noise started again now it does it when i start it up but after a few minutes it stops when im sitting but start back up when i hit the gas and the more i push the gas it gets louder and dies down when i slowing down. any help would be great thank you

Not dissing Gates, but their belt for this application is not good. When you can get it to squeal, try spraying a little silicone or belt dressing on the itensioner pully and see if the noise stops, even briefly. If it does, find a parts house that sells the Goodyear Gatorback belt and install it. See if the noise goes away. I fought this on a '99 model for two months before learning about this issue. Has something to do with the way the Gates cannot shed dirt/debris from the grooves in the belt, but the Goodyear has crosshatching in the grooves to help clear them.

Try a Goodyear Gatorback serpentine belt. I have a Gatorback on my 1991 S10 Blazer SUV and the belt and pulleys are quiet. I started to replace it with a AC Delco serpentine belt because i like my car to be ALL GM but after I looked at the wear indicator on the tensioner pulley bracket, I left the Gatorback on the engine. The good thing about the automatic tensioner is the wear indicator and you do not have to worry about over tightening or leaving the serpentine belt too loose. The serpentine belt will lose 10% of it's original installation tension within 1,000 miles. If you want a quick fix for a squeeking belt, spray some Armor All on the belt and let it dry about an hour before starting the engine. I tried that on one of my 1963 Pontiacs with a single V-belt and it was a permanent fix. I could have fixed the V-belt squeal by tightening the alternator over the limit and risk damage to to the bearing in the alternator or water pump.

My Blazer has about 145,000 miles on it and the thermostatic controlled fan clutch which I think should be replaced even though it is not squeeking. That is because when the ambient temperature is over 95 degrees, the engine runs at 195 degrees but the engine temperature climbs to 200+ degrees when idling with the A/C on. I am not too concerned about the engine temperature but I feel like a new thremo-controlled fan clutch would keep the running and the idle temperature at 195 degrees.

I had to change the fan clutch on my '02 a couple of weeks ago. Same thing, at idle in high temps (it has been 100+ here for a couple of weeks) the temp was climbing up to around 225 or so. Now it doesn't make it to the 210 mark.

The other clue was when starting out, no fan roar, which these little beasties are famous for.

I know this is an old thread but I have my truck in pieces and I'm getting desparate. I have a 2000 ZR2 and I replaced the outer seal on the front differential recently. The next day I went to check all my bolts etc to make sure all was tight (drove perfect) and found that I had torn the outer boot at some point. So I just got done taking the shaft back out and I have cut the old boot off. Now I can't for the life of me figure out how to get the outer CV joint apart to install the new boot. Tried banging the hell out of it to no avail. Any help would be appreciated!